Images of debris from Russian strikes on Ukraine strongly indicate that Moscow has used a cruise missile whose development led Donald Trump to quit a landmark nuclear pact in his first term, two experts said, confirming earlier Reuters reporting.

Iran sees the chance of a good outcome from a third round of talks with the United States, its President Masoud Pezeshkian said on Wednesday, as a delegation left for Geneva for negotiations over Tehran's nuclear program.

Secretary of State Marco Rubio held a briefing on Iran hours before the speech for Congress' "Gang of Eight" - composed of the leaders of the Senate and House of Representatives and the two chambers' intelligence committees.

Trump briefly laid out his case for a possible attack on Iran in his State of the Union speech to Congress on Tuesday, saying he would not allow the world's biggest sponsor of terrorism to have a nuclear weapon.